Use LC_ALL=C instead of LC_CTYPE=C because it works on Big Sur

It also works on the slightly older MacOS Catalina.
This script is only used on development laptops, so hopefully
this will work for more laptop OS's now.

Signed-off-by: Ryan Richard <richardry@vmware.com>

hack/prepare-for-integration-tests.sh

@@ -210,7 +210,7 @@ fi
 test_username="test-username"
 test_groups="test-group-0,test-group-1"
 set +o pipefail
-test_password="$(cat /dev/urandom | env LC_CTYPE=C tr -dc 'a-z0-9' | fold -w 32 | head -n 1)"
+test_password="$(cat /dev/urandom | env LC_ALL=C tr -dc 'a-z0-9' | fold -w 32 | head -n 1)"
 set -o pipefail
 if [[ ${#test_password} -ne 32 ]]; then
   log_error "Could not create test user's random password"